Lifting-jack.



A. P. WILSON.

LIFTING JACK.

' v APPLIOATICN FILED NOV. 18, 1909.

966,374. Patented Aug. 2, 1910.

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A. I. WILSON. LIFTING JACK."

APPLIOATION FILED NOV. 18, 1909.

966,374, P en ed Aug- 211910.

2 SHEETS-SHEET 2.

QWMMQ s I ALFONZO F. WILSON, OF WORTI-IING'ION, INDIANA.

LIFTING-J'ACK.

Specification of Letters Patent.

Patented Aug. 2, 1910.

Application filed November 18, 1909. Serial No. 528,835.

To all whom it may concern:

Be it known that I, ALFONZO F WILSON, citizen of the United States, residing at IVorthington, in the county of Greene and State of Indiana, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

My invention relates to improvements in that class of lifting jacks wherein a clutch is used which engages with a standard, and the object of'the invention is to provide an improved standard. which, while having the stiffness and rigidity necessary to the support of a heavy weight, shall yet be adapted to be engaged by the dog, clutch or other devices acting thereon.

I have shown my invention as applied to the form of lifting jack shown in my Patent No. 821,565, of May 22, 1906, but I do not wish to be limited to this application of my invention.

For a full understanding of the invention and the merits thereof, and to acquire a knowledge of the details of construction, reference is to be had to the following description and accompanying drawings, in which:

Figure 1 is a side elevation of a jack containing my improvement; Fig. 2 is a vertical section of the jack shown in Fig. 1; Fig. 3 is a transverse section of my improved supporting standard; and, Fig. 4 is a detail View of the standard, the outer portion being broken away to show the internal core.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

Referring to these figures, 1 designates the standard of a lifting jack, the same being provided at one end with a base or foot 2.

3 designates a hollow runner which is provided with a vertical circular bore 1 designed to snugly fit around the standard 1 so that the runner may move longitudinally on the standard. The runner 3 is also provided with a lifting bracket 5 and has a recess 6 which extends up through the runner beneath the bracket and opens out on one side only of the runner by means of a curved slot 7. The runner 3 is also provided with a transverse bearing opening 8, preferably concentric to the curved slot 7 and extending entirely therethrough from side to side. A headed bolt 9 extends through said slot, the shank of said bolt projecting out through the slot and being held by a nut to one end of a handle 11. The handle 11 is provided with a circular stud 13 preferably integral therewith and projecting out from one side thereof. The stud 13 is provided with an enlarged collar 12 which has a bearing within the curved slot 7, while the stud itself projects through the slot and into a correspondingly shaped bearing in the upper end of a pitman or link 14 which is free to move within the recess 6 in the hollow runner 3. The other end of the link 14; is L- shaped and is fulcrumed to a lower runner 15 which is bifurcated at its rear end to receive it, and is provided with a vertical bore 4? designed to snugly receive the circular standard 1. A spring 16 bears against the lower end of the link as shown.

The lower runner15 is provided with a gripping block 17 which is toothed or serrated on its biting face so as to accurately fit the curvature of the standard 1. The upper runner 3 is also provided with a toothed gripping block 18 which is held in the front face of a wedge-shaped finger-19 mounted in the runner at the rear side thereof. The finger projects downwardly out of the runner 3 and is provided at its end with a lug 20. A spring 21 bears against the shoulder on the said finger to press the same upward so that its toothed gripping block will be forced against the surface of the tubular standard. To retract the said finger so that its gripping block'will be carried out of contact with the standard, I have provided the cam lever 22 which is formed with a cam surface 23 and with a keyhole-shaped slot 24 by which it may be inserted through the lateral off-set finger of the lug, into engagement therewith. The cam surface of the lever is designed to bear against a shoulder 25 at one side of the runner 3.

The mechanism heretofore described is practically that previously described in my patent above mentioned, and its operation is as follows: In order to lift a load, the handle 11 is given an up and down motion like a pump handle, and this effects the alternate clutching of the runners 3 and 15 with the standard 1. WVhen the handle is raised, the gripping block 18 engagesthe standard to prevent any downward displacement of the uppermost runner which at this time supports the load. The upward movement of the handle raises the lowermost runner 15. When the handle is lowered, the gripping block in the lower runner 15 grips the standard 1, and the lower runner will then serve as a stationary support, while the uppermost runner will be raised on the standard. In this manner, the runners are actuated to alternately grip the standard so as to climb the same and raise the load to the required elevation.

One of the difficulties in lifting jacks having gripping blocks or dogs engaging the standard and biting into the same is that if the standard is made of relatively soft mablock or dog will hold, then the standard bends too easily under the weight of the object being lifted. If, however, the standard is made of hard high carbon steel so as to give it the requisite stiffness, then the dogs or gripping blocks will not take hold, but slip upon the surface of the standard, and thus the mechanism is rendered inoperative. In order to overcome this difiiculty, I have devised a post or standard for lifting jacks, consisting of a central core of high carbon steel, and surround this central core with a casing or tubing of relatively soft malleable steel. By this means, I get a standard of great stiffness, but with an outer surface of soft steel or iron into which the teeth on the dogs or gripping blocks will easily bite and hold.

In the application of my improvement to the particular form of jack which has been heretofore described, I form the outside of the standard 1 of a tube of malleable iron or steel, relatively soft, so that the gripping dogs or blocks may easily bite into the surface thereof, while interiorly of the outer tube 1 I provide the square stiffening rod 1*, this rod extending down to and being mounted in the base 2, as is the outer tubular portion 1.

While I have shown this improvement as applied to the lifting jack described in my prior application, I do not wish to limit myself to this particular form of lifting jack] as it is obvious that my composite standard might be equally well applied to any form of lifting jack wherein is included a supporting post or standard and dogs, pawls or gripping blocks engaging the supporting post. I have shown the gripping blocks as being mounted upon movable runners, and the post or standard as being fixed upon a base, but it is to be understood that my invention is equally applicable to a vertically movable post or standard movable within a fixed casing having gripping dogs.

Having thus described the lnvention, What .Iclaim is: terial, such as soft steel so that the gripping 1. In a lifting jack having a gripping dog, a standard movable relatively to the dog,

said standard being composed of an inner core of rigid and hard. material, and an outer covering of relatively soft and malleable material, the gripping dog havingbiting engagement with the standard.

2. In a lifting jack having a gripping dog, a standard engageable by said gripping dog, said standard consisting of an outer tube of relatively soft and malleable metal, and an inner core inclosed Within the tube, composed of relatively stiflF-and-rigid metal, the gripping dog having biting engagement with the standard.

3. In a lifting jack having a dog, a stand-. ard with which the dog has biting engagement, said standard comprising an outer tube of relatively soft and malleable metal,

and an inner core, square in section and made of relatively hard and rigid metal.

4. A lifting jack including a base, a standard projecting up from the base, and a run ner movable along said standard and hav-. ing a dog in biting engagement therewith, said standard being composed of an outer tube of relatively soft and malleable material, and an inner square core of relatively stiff rigid material.

In testimony whereof I affix my signature inpresence of two witnesses.

ALFONZO F. WVILSON. [n s.1 

